In tunnel mining, movable (mobile) mining machines with which a tunnel shaft can be driven, in particular even in hard rock, have long been known. Corresponding tunnel boring machines, which have a cutting wheel as a tool drum on the front side of a machine frame, with cutting discs arranged on the circumference of the cutting wheel, are known for example from U.S. Pat. No. 4,548,442 or U.S. Pat. No. 5,234,257.
The invention is based on a mining machine and a method according to WO 2010/050 872 A1. The corresponding machine is intended both for driving tunnels and also generally for mining extraction and operates like the other known tunnel boring machines with a tool drum which rotates about a drum axis and on the circumference of which a multiplicity of stripping tools in the form of cutting discs are arranged in a distributed manner and directed radially outwards. By means of a boom, at the front end of which the tool drum is mounted, and a swinging device, with which the boom can be swung in relation to the movable machine base frame, the removal of material at the working face, also known as the drift or heading face, is performed ahead of the cutting head by swinging the cutting head back and forth. In the case of the mobile mining machine known from WO 2010/050 872, the cutting discs can rotate freely in their suspension, the cutting discs being arranged distributed over the circumference of the tool drum in such a way that the axes of rotation of some cutting discs are parallel to the axis of rotation of the tool drum and the axes of rotation of other cutting discs are oblique to the axis of rotation of the tool drum. The distributed arrangement of a multiplicity of cutting discs is intended to have the effect that, with every swinging movement, material is only partially removed with each cutting disc, in order in this way to minimize the stressing of the individual cutting discs and to this extent the wear of the stripping tools on the cutting wheel. The swing axis for the swinging movement extends essentially perpendicularly, at least to the undercarriage of the machine base frame, and the boom can be raised or lowered by way of a tilting cylinder, in order to extract material with the cutting wheel at different heights or seams. According to one configuration, the swinging movement of the tool drum is performed along an arcuate face, which is formed at the front end of the boom. Furthermore, WO 2010/050 872 also discloses a configuration of a mining machine in which there are two or three cutting wheels, these cutting wheels then respectively being able to swing inwards and outwards in relation to the machine base frame about a swing bearing. The individual cutting wheels are intended in this case to be suspended from a frame, which can be turned about the longitudinal axis of the tunnel in order to allow a tunnel to be driven and advanced with the oppositely movable cutting wheels, which themselves can only be swung perpendicularly to the axis of rotation of the tool drum, by turning of the frame receiving the number of cutting wheels.
Apart from driving tunnels with cutting discs, which are in principle passively cutting, the applicant's US 2010/001 574 A1 or U.S. Pat. No. 7,631,942 B2 also discloses mining machines that operate in a milling or drilling manner with self-rotating stripping tools arranged on a rotatable drum. The actual stripping tools on these mining machines consist of individual cutter tips, which rotate, usually at a high rotational speed, about the axis of rotation of a tool carrier, a number of tool cutters being respectively arranged on a tool carrier and at the same time the rotation of the tool drum having the effect that only individual cutters of a tool carrier are respectively in contact briefly with the rock to be extracted. Since in the case of these mining machines only a few cutter tips or only a single cutter tip is/are respectively in contact with the rock to be extracted, a relatively low pressing force is required, although nevertheless a high stripping force can be achieved.